Hoisting submerged objects is always difficult, but when it’s a priceless Civil War relic that has been submerged for 136 years, difficult doesn’t begin to describe the process needed to make this lift!
The H. L. Hunley, a Confederate-made submarine, sank several vessels during the Civil War before it too sank in 1863 near Charleston, SC. In August 2000, it was raised using a 600 ton lattice boom crane mounted upon the jack barge Karlissa B.
The rigging was by far the most difficult part of the task. First, a steel frame was fabricated to encompass the length and breadth of the Hunley. Thirty-two nylon, web straps were hung from the frame running under the keel to support the full length of the submarine. Each strap was equipped with a bag filled with liquid foam which hardened it take the shape of the keel. All thirty-two straps had a dynamometer attached so as to measure and adjust the tension.
Hoisting the Hunley and frame without damaging it was no easy task either. With the barge secured to the sea floor by its jacks, providing a stable platform for the crane to operate, the Hunley was hoisted. The process was slow as it could only be hoisted a few inches at a time so its movement through the water would not crush it. Finally, the frame was laid softly and safely on the transport vessel that was being tossed by waves.
It was a very delicate process, but in the end, the Hunley made out safely and was taken to the LASH Conservation Center in the Old Charleston Navy Base where it was submerged during the archeological survey & excavation for twelve years. It is now located at Warren Lasch Conservation Center in North Charleston, SC.
What was the most popular form of transportation on the job site in the 1930’s?
Before OSHA, the crane hook hoisted construction personnel up to begin work. Over 3,000 construction personnel worked to build the Empire State Building, five of which lost their lives.
Construction began in 1930 and took less than 14 months to complete. It was the first commercial fast-track project, which is modeled in the industry today. During that time, buildings such as the Empire State Building where built using a series of derricks.
The Empire State Building just celebrated it’s 83rd birthday. For 40 years it stood as the tallest building in the world. Today, it still stands as one of the tallest structures in the United States.